There are now existing various methods for forming a suspension of coal in ordinary water or polluted water. However, it is very difficult to add hydrocarbons to such a suspension, because any added hydrocarbon will become adsorbed on the coal particles and will thus form a sludge which will float in the original water phase. For the same reason, it is impossible to grind coal in water and in the presence of hydrocarbons. The objective of the present invention is to overcome these drawbacks.